1. Field of the Invention
The invention generally relates to luminaries, and more specifically to an LED cyclorama light.
2. Description of the Prior Art
Large curved curtains or screens as backgrounds for stage settings have been used for many years. Such curtains or screens are frequently referred to as cycloramas (“CYCs”). Frequently such cycloramas also include a series of large pictures, as of a landscape, placed on a wall of a circular room so as to appear in natural perspective to a spectator standing on the set in the center. However, in the field of lighting, to which this invention relates, a cyclorama or a “CYC” is a vertical surface used to form the background for a theatrical setting, usually made of heavy cloth drawn tight to achieve a smooth flat surface. With appropriate light projected on it, it usually represents the sky or suggests limitless space. Traditionally, cycloramas were horizontally curved but may now also be flat or vertically curved as well. Examples of cycloramas are discussed generally in U.S. Pat. Nos. 3,989,362; 4,123,152; 4,512,117; and 4,893,447.
While CYC lights have been known and have also been used for many years, they have had a number of disadvantages. In the past, CYC lights were difficult and inconvenient to work with in providing desired light distributions on a cyclorama. Aside from being bulky and heavy, known CYC lights have not always provided the desired light distributions or the necessary ranges to cover different cyclorama configurations. This was particularly true when the same CYC lights were used to provide lighting for both flat and curved screens. Prior CYC lights have also had some difficulty in adjusting for non-level surfaces when these lamps are mounted on a floor or a stage. Lighting personnel have been required to use numerous objects that they placed under the light to adjust the angles of the light and the positions of shadow lines and/or to compensate for a non-level floor. The adjustments required were difficult and inconvenient to make. U.S. Pat. No. 6,220,731 issued to Altman Stage Lighting Co., Inc. discloses an easily adjustable cyclorama light or CYC light, which is a luminaire that could be mounted at the top and/or the bottom of a cyclorama in order to light it in smooth, substantially uniform manner.
Also, because CYC lights tend to emit significant amounts of light over relatively large areas, the lamps used for these lights tend to get very hot, thus also heating the luminaire itself. Failure to adequately cool the bulbs has caused the lights themselves to become extremely hot as well as to cause the deterioration of gel color filters used therein, and even caused damage to the reflectors. Overheating of the lamp housings also presented danger of injury to the lighting staff as well as others in proximity to these lights.
Other disadvantages of prior CYC light included the inability of such lights to accommodate more than one size lamp or bulb. However, because there are a number of different lamp sizes, a standard lamp could not always be substituted and only the lamp for which the light was specifically designed could be used to replace a burned out lamp.
Additionally, CYC lights have traditionally utilized monochromatic light sources, such as incandescent bulbs, quartz or halogen bulbs. In order to achieve the desired lighting effects, such as the simulation of a blue sky or a different colored background, filters were typically used through which the light source transmitted the light. “Gel” filters were frequently used for this purpose. Changes in colors were difficult or inconvenient to achieve, requiring that filters be physically changed since the light output remained at a constant temperature from the monochromatic light sources. This did not promote the use of frequent or rapid changes in colors or effects or even variations or ongoing color changes. Additionally, because colored filters needed to be used to provide desired colored light, the number of colors that were achievable were necessarily limited to the number of the light filters that were available. These were normally a relatively small number of filters and obtainable colors.
3. Summary of the Invention
Accordingly, there is an object of the present invention to provide a CYC light that does not have the disadvantages inherent in prior art CYC lights.
It is another object of the present invention to provide CYC light that is simple in construction and economical to the manufacturer.
It is still another object of the present invention to provide a CYC light that utilizes arrays of LEDs as the primary sources of light.
It is still another object of the invention to provide a CYC light as in the previous object in which the LED light arrays are formed as RGBA clusters of LEDs that are individually controllable to allow light to provided having desired color outputs without the need for colored filters.
It is a further object of the present invention to provide a CYC light that includes an optically efficient reflector that provides a desired, substantially uniform distribution over substantial set areas of cycloramas or surfaces over which the light is projected.
It is still a further object of the present invention to provide a CYC light as in the previous object that uses a bank of LED clusters resulting in less heat generation and providing greater reliability than by using other light sources.
It is yet a further object of the present invention to provide a CYC light of the type under discussion that utilizes LED clusters that render the CYC light more efficient and safer to personnel to use.
It is an additional object of the present invention to provide a CYC light that can be adapted to illuminate flat as well as curved screens.
It is an additional object of the present invention to provide a CYC light that can be easily and quickly converted between ground CYC and sky CYC applications, or any other applications requiring the desired projected light patterns or distributions on a large screen or surface.
It is also an object of the present invention to provide a CYC light that utilizes a reflector and banks of LED light emitted arrays that are enclosed by an optical lens whose optical characteristics or properties can be modified to provide a large variation of projected light patterns or distributions, the reflector and/or the lens being provided with random surface texture to scatter the light and reduce or eliminate shadows or sharp discontinuities in the projected light pattern.
In order to achieve the above objects, as well as others that become evident hereafter, a CYC light in accordance with the present invention comprises a generally enclosed housing forming an interior compartment having a normally horizontal housing axis and an open front defining a window generally arranged within a plane parallel to said housing axis. A reflector substantially covers said window and has an operative portion that has a substantial uniform cross-section along said housing axis. An LED light emitter array extends along a line substantially parallel to said housing axis, the reflector having a surface configuration and said LED emitter array being arranged in relation to said reflector surface to provide a higher flux density directed toward a far end of a wall or surface to be illuminated and provide a lower flux density directed toward a near end of the surface to be illuminated in relation to the position of the CYC light, and providing a transitional flux density between the far and near ends of the surface to be illuminated. Means are advantageously provided for eliminating shadows in the projected light over the entire illuminated surface.
In accordance with a feature of the invention, the optical lens is positioned between the LED array and the reflector, said LED array and said lens together forming a generally symmetrical light flux source having a central primary axis and two secondary optical axes each angularly offset from the primary optical axis. Said flux light source is arranged in relation to said operative portion of the reflector to reflect light from the light flux source a higher flux density directed toward a far or remote end of the surface to be illuminated and reflect light from said light flux source a lower flux density directed toward the near or proximate end of the surface to be illuminated, a transition flux density being projected between said far and near ends of the surface.